Throttle valve



July 23, 1940.

B. SMITH THROTTLE VALVE Filed Dec. 14, 1938 INVENTOR BERT SM/TH.

ATTORNEY Patented July 23, 1940 UNITED STATES THROTTLE VALVE Bert Smith, Teaneck, N. J., 'as signor to American Throttle Company, Inc., New York; N; Y.-

Application December 14, 1938, Serial No.'245,587

This invention relates to throttles of the multiple type and particularly to improvements in the valve elements of such throttles.

In one form of multiple throttle which is extensively used the valve elements have slotted stems at their lower ends and each is operated by a cam carried by a rock shaft and engaging a lift surface at the upper end of the slot. To reduce wear and thus lengthen the life of the valves it is customary to deposit stellite or other wear resisting metal or alloy on the lift or wear surface through which a valve'is operated. It is rather difficult to deposit metal in this nearly inaccessible location at the upper end of the slot in the stem and it is also difficult to grind this wear surface. Therefore, it is an object of the present invention to provide a valve element having a lift element on which a wear resistant metal may be readily deposited and ground either in the initial manufacture of the valve or when repair is required.

In the accompanying drawing the single figure is a fragmentary, longitudinal sectional view of a superheater header in which the throttle is embodied.

The superheater header ii] is formed with outer chambers II and i2 separated from an intermediate chamber l3 by partitions I 4 and I5, respectively. In the partition I4 are a number of ports I6 arranged in a straight line while the partition I5 is formed with circular openings I7 alined with the ports 16. The flow of steam from the chamber II to the chamber l3 through each port I 6 is controlled by a valve comprising avalve disk 20 carried by a stem 2| which is also provided with a piston, designated as a whole by the numeral 22, fitting in the opening H in the partition l5. Associated with each piston 22 is a slotted stem or stirrup member 23 having a slot 24 for receiving a cam 25' carried by a rock shaft 26 which extends longitudinally through the chamber l2 below partition H. The cams 25 on rock shaft 26 may operate the valves 20 simultaneously or, as shown, in sequence from left to right when a throttle lever connected to the rock shaft 26 is operated.

As illustrated for the valve at the left of the figure, piston 22 comprises an enlarged head 30 at the end of valve stem 2! and a cap 3| threadedly engaged with the head and locked in place by spot welds 32 at several points. Alternatively, a continuous weld may be employed between the perimeter of the head 3!] and cap 3| or set screws may be threaded into tapped openings located in part in the head 30 and in part in the cap 3| along their line of junction. The upper end of the stirrup member 23 has a circular flange 33 and the cap 3| an inwardly extending flange 34 adjacent an opening 35 in its end wall through which the stirrup projects, these flanges provid-i 5 ing interengaging shoulders holding the stirrup in place. This arrangement provides a swivel connection between the stirrup 23 and the piston 22 to permit valve disk 20 to be turned for grinding it on its seat 21, as described in Pippy Patent 10 1,863,068 issued June 14, 1932.

The stirrup 23 is formed with a bore 36 (extending from its upper end to the slot 24) in which is mounted a lift member 31 having a wear surface 39 of stellite, or other wear resisting 15 metal or alloy, engageable by the cam 25. Although the lift member 31 may be made integral with and as a projection from the end of stem 2|, or more specifically the head 30 thereof, it is preferably a separate element and is held in place 20 by interengaging shoulders formed by a flange 23 at its upper end.

In some earlier constructions of valves of this type the stellite wear surface has been deposited on the upper end wall of the slot 24 in the stirrup member 23. In such constructions it is diflicult and it is also difiicult to subsequently grind the 30 ent invention has the advantage that when the lift member having an unworn wear surface 39 When the lift member 3a of the cap member 3| and stirrup member 23 40 member and having a wear surface engageable 5 adjacent the head of said stem and having a Wear surface on its other end engageab le by said cam; and interengaging shoulders on 'said stirrup member adjacent the bore therein and on said lift member for detachably mounting the latter in said stirrup member.

3. In a valve structure having a stem provided at one end with an enlarged head; a cam for actuating said valve; a projection extending axially from the end of the head on said stem and having a Wear surface engageable by said cam; and a stirrup member detachably secured to the head on said stem and having a bore receiving: said projection and a slot receiving said cam.

4. In a valve structure having a stem provided at one end with an enlarged head, and a cam for actuating said valve; a stirrup member formed with a slot for receiving said cam and also with a bore that is concentric with the axis of said stem and which extends to said slot; a stirrup member having a bore receiving said projection and a slot receiving said cam; a cylindrical cap detachably secured to said head on said stem and having an aperture in its end wall through which said stirrup projects; and interengaging shoulders formed on said cap and stirrup member for securing the latter to said stem.

BERT SMITH. v 

